Weston Investment Group Pty Ltd v City of Parramatta Council

Background

1. The Site is an irregular shaped allotment having a total site area of 4,672m2 with a primary front boundary to Weston Street of 60.3 metres, an eastern boundary of 77.4 metres and a combined rear boundary of 77.4 metres.
2. The Site has a cross fall from the street to the north-eastern corner of approximately 3.3m. It is occupied by two single residential dwellings.
3. The Site is identified as coloured yellow in the aerial photograph set out below: Figure 1: Aerial photograph extracted from the Council's Statement of Facts and Contentions filed 17 February 2022 (Ex 1 - SOFAC).
4. The Site is located within the R4 High Density Residential zone of the Parramatta Local Environment Plan 2011 (PLEP 2011).
5. The R4 High Density Residential zone is undergoing a period of transition having a mix of single storey and residential flat buildings. The properties immediately adjoining the site are a single dwelling to the west and a residential flat building to the east.

Environmental Planning and Assessment Act 1979 8.7 Appeal by applicant - applications for development consent (cf previous s 97) (1) An applicant for development consent who is dissatisfied with the determination of the application by the consent authority may appeal to the Court against the determination. (2) For the purposes of this section, the determination of an application by a consent authority includes - …… (b) any decision subsequently made by the consent authority as to a matter of which the consent authority must be satisfied before a deferred commencement consent can operate. ……

Environmental Planning and Assessment Regulation 2000 95 Deferred commencement consent (cf clause 67 of EP&A Regulation 1994) (1) A "deferred commencement" consent must be clearly identified as a "deferred commencement" consent (whether by the use of that expression or by reference to section 4.16(3) of the Act or otherwise). (2) A "deferred commencement" consent must clearly distinguish conditions concerning matters as to which the consent authority must be satisfied before the consent can operate from any other conditions. (3) A consent authority may specify the period within which the applicant must produce evidence to the consent authority sufficient enough to enable it to be satisfied as to those matters. (4) The applicant may produce evidence to the consent authority sufficient to enable it to be satisfied as to those matters and, if the consent authority has specified a period for the purpose, the evidence must be produced within that period. (5) If the applicant produces evidence in accordance with this clause, the consent authority must notify the applicant whether or not it is satisfied as to the relevant matters. (6) If the consent authority has not notified the applicant within the period of 28 days after the applicant's evidence is produced to it, the consent authority is, for the purposes only of section 8.7 of the Act, taken to have notified the applicant that it is not satisfied as to those matters on the date on which that period expires. Note - See also section 6.29 of the Act and clause 161 of this Regulation

1. Council continues to press Contention 3 in Ex 1 - SOFAC, and in particular compliance with Particular 3 (a) (ii) and (ii) which is set out below: "(a) condition 2 of Schedule 1 provides as follows: On-site Detention System: The on-site detention facility shall not be located within the subfloor of a habitable area. In this regard the proposed on-site detention facility shall be relocated away from its currently proposed location. Revised stormwater drainage plans shall be submitted to Council for assessment and approval and shall include: (i) Relocation of the OSD facility. (ii) The entire pipeline connecting the subject site to Council's stormwater infrastructure in Hope Street. The plan shall also demonstrate the easements' functionality as an overland emergency flowpath from the subject site to Hope Street. (iii)A cross section of the overland flow path within the easement. A longitudinal section of the pipeline within the easement. It is to be demonstrated that the existing and proposed pipelines from the subject site to the discharge point in Hope Street is adequately sized. Calculations demonstrating this shall accompany the application for the Construction Certificate for approval by the certifying authority.

To provide consistency, all plans including engineering, architectural and landscaping shall be revised to reflect the above changes. Reason: To ensure compliance with Council's Stormwater management controls and best practice."

1. The drainage engineers (Mr S Haddad for the Applicants and Mr G Gavel for the Council) agree that particular 3 (a) (i) has been met (Ex 3, Joint Expert Report filed 6 May 2022, p 6).
2. Contention 3(a)(ii) and (iii) remain unresolved in relation to: (a) "The plan should also demonstrate the easement's functionality as an overland emergency flowpath from the subject site to Hope Street." (b) "It is to be demonstrated that the existing and proposed pipelines from the subject site to the discharge point in Hope Street is adequately sized…".
3. There are no development standards applicable to the contention. The applicable policies and guidelines are as follows: 1. Parramatta Development Control Plan 2011 (PDCP 2011): City of Parramatta: Development Principles (Ex 2, tab 5, p 43) (Development Principles) 2. City of Parramatta: Development Engineering Design Guidelines (Ex 2, tab 9, pp 289 and 294) (Policy). 3. City of Parramatta: Stormwater Disposal (Ex 2, tab 10, pp 315, 316, 318 and 321) (Guidelines). 4. Upper Parramatta River Catchment Onsite Detention Handbook, 4th Edition (Ex 2, tab 8, p 81) (Handbook).
4. Ms Sims made the following tenders and submissions on behalf of Council: 1. Tendered Ex 1 Respondent's Statement of Facts and Contentions filed 17/02/2022; Ex 2 Respondent's Bundle of Documents filed 14/04/2022; and Ex 3 Joint Experts' Report in Civil Engineering/Stormwater by Mr Haddad for Applicant and Mr Gavel for the Respondent filed 06/05/2022. 2. In relation to Deferred Condition No. (2) of Schedule 1 of DA/267/2018: 1. Particular (ii), the pipeline is shown, but the capacity of that pipeline is the concern, fundamentally as an overland emergency flow path. 2. Particular (iii), in the sense that the pipeline as shown "to the discharge point in Hope Street is adequately sized". 1. By "adequately sized" the pipeline needs to be sufficiently sized to accommodate the 1% AEP flow, and that the overland flow path is for emergencies where either the pipeline is blocked or the rainfall is greater than 1% AEP. 2. Or there is a total blockage in the OSD, or pipe together with an exceedance of the 1%AEP event. 3. The design for the stormwater drainage is not in accordance with Council's policies or best practice for the following reasons: 1. PDCP 2011 (Ex 2, Respondent's Bundle of Documents, tab 5, pp 42-43): 1. The relevant Objectives for Stormwater Drainage par 3.3.6.1: "0.1 To minimise the quantity of stormwater run-off including changes in flow rate and duration by disconnecting impervious areas. 0.4 To minimise surcharge from the existing drainage systems. 0.5 To minimise and control nuisance flooding and to provide for the safe passage of less frequent floods." 1. Design Principles: "P.6 Adequate provision is to be made for the control and disposal of stormwater run-off from the site to ensure that it has no adverse impact on council's stormwater drainage systems, the development itself or adjoining properties. Stormwater drainage design criteria are to be in accordance with Council's stormwater Disposal Policy and current Design and Development Guidelines. P.7 On-site detention (OSD) will be required as outlined in the Upper Parramatta River Catchment Trust On-Site Detention Handbook, subject to compliance with Council's Stormwater Disposal Policy and current Design and Development Guidelines. P.8 Stormwater, including overland flows entering and discharging from the site, must be managed. The site drainage network must provide the capacity to safely convey stormwater run-off resulting from design storm events listed in Council's Design and Development Guidelines." 1. City of Parramatta Stormwater Disposal Policy (Ex 2, tab 10, pp 315, 316, 318 and 321) 1. Par 3.1: Objectives of the Policy: first bullet point: "That OSD design and the method of discharge are appropriate to the site and its surroundings and consistent with Council design requirements". 1. Par 3.2: Fundamental Principles of the Policy: the first and last 2 bullet points on p 316: "Stormwater management is to be considered in a cumulative and long term context to maintain and improve the flow of stormwater. Stormwater runoff must not adversely impact surrounding properties and Council infrastructure and assets through the diversion and concentration of flows. Overland flow is to be considered and managed in designing an on-site stormwater system." 1. In the Definition on p 321: "Inter-allotment drainage easement - a reservation of land over public or private downstream property/ies to enable a pipe to be laid to drain OSD by gravity from a development site to Council drainage infrastructure." 1. City of Parramatta: Development Engineering Design Guidelines, June 2018 (Ex 2, tab 9) 1. Par 3.6.1 on p 308: Overland flow path/swale design criteria "a) Calculations demonstrating that the swale has capacity to cater for all external flows entering the site as a result of all storm events up to and including the 1% AEP storm event. b) The proposed swale shall be designed using the minor/major system design principles noted in the Australian Rainfall and Runoff 1987. c) Flows generated by the local upstream catchment can be quantified using Rational Method or DRAINS. d) Floatable material (bark or timber mulch) shall not form part of the swale." 1. Par 3.6 on p 308: Inter-allotment Drainage Easement "The following shall be included in the stormwater drainage plans where it is proposed to drain into an easement: a) The inter-allotment drainage system within the easement shall be designed to cater for the 1% AEP storm event and includes a surface swale to control flows in cases of surcharge." …….. 1. Upper Parramatta River Catchment Onsite Detention Handbook, 4th Edition (Ex 2, tab 8): 1. Definitions on p 81: …. "Overland Flowpath: Surface drainage system that caters for minor flow from an upstream catchment. Also the drainage system that caters for surcharges from the OSD storage in events larger than the 100 year ARI flow or when a blockage occurs." …… 1. On Council's case the Applicant's appeal should be refused.
5. Mr Lazarus SC for the Applicant, opened by requesting confirmation of Council's case identified by Ms Sims, in view of the fact that during the on site view Mr Gavel raised 5 separate matters which were not raised in Council's Contentions (Ex 1) as follows: 1. Issue of entry of overland flow from Weston Street. 2. Whether the low bushes were an impediment (at the rear of 9-11 Weston Street). 3. Any risk of the water over-topping and falling into the kerb (on 12-16 Hope Street). 4. Use of treated timber at the bottom of the fence (on 9-11 Weston Street). 5. The retaining wall (on 12-16 Hope Street) being potentially stretched.
6. Ms Sims confirmed that the issues raised on the site view as set out above would not be pressed by Council. The issues remain as set out by Ms Sims above.
7. Mr Lazarus SC made the following tenders/submissions on behalf of the Applicant: 1. Tendered Ex D: Letter from Mr S Haddad dated 16 May 2022 setting out the sizing of overland flowpath to cater for emergency overflows of stormwater. 2. The Applicant's case rests on the documents as set out in Ex 2 Council's Bundle of Documents as detailed below: 1. Tab 5: PDCP 2011, Part 3 Development Principles: relevantly par 3.3.6.1 Stormwater Drainage - Design Principles p 43: P.6, P.7 and P.8 - policy documents are called up in different ways and for different purposes: "P.6 Adequate provision is to be made for the control and disposal of stormwater run-off from the site to ensure that it has no adverse impact on Council's stormwater drainage systems, the development itself, or adjoining properties. Stormwater drainage design criteria are to be in accordance with Council's Stormwater Disposal Policy and current Design and Development Guidelines. P.7 On-site detention (OSD) will be required as outlined in the Upper Parramatta River Catchment Trust On-Site Detention Handbook, subject to compliance with Council's Stormwater Disposal Policy and current Design and Development Guidelines. P.8 Stormwater, including overland flows entering and discharging from the site, must be managed. The site drainage network must provide the capacity to safely convey stormwater run-off resulting from design storm events listed in Council's Design and Development Guidelines." 1. P.6 - references adequate provision for stormwater runoff in accordance with the current Guidelines. 2. P.7 - design of OSD as outlined in the Handbook (this is the only reference to the Handbook), and not inter-allotment drainage assessment over 2 properties - OSD compliance is with Policy and Guidelines. 3. P.8 - the drainage network must provide the capacity to safely convey stormwater run-off. The table in Ex D sets out this design guideline evidence that P.8 calls up. 1. Ex 2, tab 10, City of Parramatta Stormwater Disposal Policy - the definition of "Inter-allotment drainage easement" on p 321 does not exclude surface drainage. 2. Ex 2, tab 9, p 283: Development Engineering Design Guidelines: 1. Section 1: Drainage: par 1.0 Introduction: "This guidelines is intended to set out Council's requirements for the design of stormwater drainage and other engineering elements associated with development. It is not intended to be a comprehensive design manual nor a stand-alone document but rather to be read in conjunction with relevant instruments, policies, codes, industry guidelines and standards including: …… p) Stormwater Disposal Policy" …… 1. Section 4, par 4.2, p 289: Private Drainage Easement "Where the development site falls away from the street and no Council pipe exists within the property, an easement to drain over downstream properties will be required to drain the development. The easement shall be located on the lowest side of the site. The System shall be designed to sufficiently convey all runoff from the development site and when draining developments with OSD shall be designed to cater for emergency overlows of the OSD system in all storms up to and including the 100 year ARI storm event. Where the system is proposed through multiple properties, the system shall be designed to cater for any additional flows which can be directed into the system from those sites. Pits shall be located at the downstream end of the drainage system within the development site and at the downstream end of the system within each downstream property. Where it is proposed to connect to an existing easement, calculations to demonstrate that there is sufficient capacity to cater for the development site in addition to any existing flows is required." ……
8. Mr Lazarus SC drew the Court's attention to the words "network" and "system" which in this case includes the stormwater pipe plus overland flow to establish the design to dispose of the stormwater. 1. Section 5, Stormwater Drainage Design Standards, par 5.1 on p 294: "Average Recurrence Intervals: The following average recurrence intervals (ARI) shall be used for stormwater drainage design relating to development - relevant extracts - "Component Design ARI (Years)" Inter-allotment drainage (where a flow path for flow in excess of the pipe capacity has been provided) 20 Inter-allotment drainage (pipe only) 100 Street drainage 20

1. Reference was also made to par 5.2 : Internal Stormwater Drainage Pipes …."shall be designed in accordance with the requirements of AS/NZS 3500.3:2018"; and par 5.3 Internal Stormwater Drainage Pits: "Stormwater pits or cleaning eyes shall be provided at the following locations where appropriate to provide access and maintenance functions….." 2. Section 3: OSD Design, particularly par 3.6.1 and 3.6 on p 308: Inter-allotment Drainage easement, sub-par "a) The inter-allotment drainage system within the easement shall be designed to cater for the 1% AEP storm event and includes a surface swale to control flows in cases of surcharge…." 1. Ex 2 tab 8, Upper Parramatta River Catchment Trust - On-site Stormwater Detention 4th Edition December 2005: This document is only relevant in so far as it applies to the OSD drainage system, and that is not the subject of these proceedings. It is the capacity of the pipes draining the stormwater which Council is questioning, not the OSD as constructed. 2. There was a discussion between counsel on 16 May 2022 in the afternoon regarding whether or not Ex D gave sufficiently accurate information. As a result of that discussion, Mr Haddad undertook to review Ex D and 2 Stormwater Drainage Plans overnight, being plans SW300 Rev E and SW204 Rev E (Ex B, tab 11). 3. On 17 May 2022, Mr Lazarus SC tendered the following: 1. Mr Haddad's letter dated 17 May 2022: Sizing of Overland Flowpath to Cater for Emergency Overflows. This letter was substituted for Mr Haddad's former letter dated 16 May 2022, and became Ex D. 2. Stormwater Concept Plans drawings no. SW300 Rev F and no. SW204 Rev F became Ex E, and were substituted for the Rev E version of those 2 plans in Ex B tab 11. 1. Ex D: Sizing of Overland Flowpath to Cater for Emergency Overflows commences with the first 3 paragraphs: "This document provides details of the overland flowpath capacity and assesses the capacity of the existing flowpath to carry the emergency overland flows from the proposed development and the existing developments that drain into the easement line. The document also details the additional works proposed to ensure that the easement is able to carry the 1% AEP flows in the event of an emergency (ie partial or full blockage). It is worthwhile noting that the occurrence of a 1% AEP rainfall event coinciding with the full blockage of all OSD systems draining to the easement is a very unlikely event. It is unrealistic to expect the easement to function as an overland flowpath in a 1% AEP event assuming the pipe is fully blocked." 1. Mr Lazarus SC explained the updated Ex D and the plans in Ex E as showing: 1. The ability of the system to deal, by way of surface flows, with the 1:100 year flood event in the event there is a 50% or 100% blockage of the pipe, noting the added improbability of a significant or complete blockage of the pipe together with a 1% AEP. 2. In relation to the 9-11 St Easement as shown on the plans in Ex E, and the longitudinal cross section of E-E, the narrow section of the path on 9-11 Weston Street is not wide enough to carry the emergency flows in case there is a blockage in the pipe. In that scenario, the Applicant recommends that the existing timber edge on the fence side of the easement on 9-11 Weston Street be raised by 40mm as a minimum to achieve the depth that is needed for the water to be conveyed downstream. 3. In relation to longitudinal Section F-F as shown on Ex E, the Applicant understands that there is an objection by Council relating to the wood mulch on the 9-11 Weston Street Easement that could become flowable in the event of an emergency overland flow. The Applicant suggested that the wood mulch be replaced with pebbles or similar material that would not be transported by emergency stormwater flows when there is a pipe blockage or flows above the 1% AEP. 4. In relation to the possibility (however remote) that the emergency stormwater flow may impact the area behind the rear retaining wall on the 12-16 Hope Street Easement, the Applicant has suggested the construction of a concrete kerb 120mm high to contain the emergency stormwater flows within that part of the easement.
2. In relation to Ex D and Ex E, which are to be read together, I note: 1. The longitudinal section H-H on plan SW204 Rev F is at the beginning of the 9-11 Weston St Easement. This pipe has capacity for the 1% AEP stormwater flow, and the surface flow is to cater for the flow above the 1% AEP and/or a blockage in the pipe. Mr Haddad considers that stormwater drainage system is satisfactory at this point, although in emergency it will encroach outside the easement of 1.2m by 80cm with a flow depth of 0.13cm (plans SW300 Rev F and SW204 Rev F). Mr Gavel challenges this part of the drainage system. 2. The longitudinal section G-G on plan SW204 Rev F (Ex E) is at the middle of the 9-11 Weston St Easement. This pipe has capacity for the 1% AEP stormwater flow, and the surface flow is to cater for the flow above the 1% AEP and/or a blockage in the pipe. Mr Haddad considers that stormwater drainage system is satisfactory at this point although in emergency it will encroach outside the easement of 1.2m at a depth of 20cm across the paved footpath (plan SW300 Rev F). Mr Haddad has recommended increasing the timber panel against the fence to contain that flow. Mr Gavel challenges this part of the drainage system. 3. In relation to the 9-11 Weston St Easement, and the area identified on plan SW204 Rev F as longitudinal section F-F, to counter an objection raised by Mr Gavel on the on site view in relation to the possibility of the mulch flowing and causing an obstruction during a flood event, Mr Haddad has suggested replacing the timber mulch with pebbles or similar material which will not move during a flood event. 4. The longitudinal section E-E on plan SW204 Rev F is adjacent to the rear boundary fence of the 12-16 Hope St Easement. The pipe is sized for the 5% AEP event (225mm diameter), with between the 5% and the 1% AEP using the surface swale. Parallel with, and 4.6m from, the rear boundary fence of 12-16 Hope Street, there is constructed a block retaining wall, as identified on plan SW300 Rev F noting section E-E. In order to contain the overland emergency flows within the 1200mm easement width, Mr Haddad has recommended the construction of a concrete kerb 120mm high (Ex D, par (4), p 2 and as shown on Ex E plan SW300 Rev F). Mr Gavel challenges this part of the drainage system. 5. The stormwater pipe from the rear boundary of the 12-16 Hope Street Easement, through the 12-16 Hope Street Easement to Council's drainage pit in Hope Street, is referenced by longitudinal sections A-A, B-B and C-C on plan SW204 Rev F and SW300 Rev F. The flow for longitudinal section B-B is detailed on p 6 of Ex D. The width of the overland flowpath is 0.18m wider than the easement but the existing width between the solid walls on each side of the easement is 1.5m. Ex D, par (1), p 2: "The width of the overland flowpath is 180mm wider than the easement but this is based on the existing width between the solid walls on each side. There is no benefit in reducing the width to meet the 1200mm width. However, to demonstrate that the 1200mm width is sufficient, we have shown additional calculations to reflect both the 1200mm and the 1380mm width."

Experts' Evidence

1. During the hearing the experts did not resile from the position they expressed in Ex 3: Experts' Joint Report filed 6 May 2022. The positions expressed on p 5 of Ex 3 are as follows: 1. Mr Haddad for the Applicant: "…the easement pipe in the downstream properties is adequate to accept and convey the flows from the proposed development at 15-19 Weston Street, Rosehill. This is because the pipe should only have the capacity to drain the 5% AEP (20-yr ARI) flows as per council DCP and as accepted in general practices in the industry which are detailed in the following sections of this report" (meaning Ex 3)." 1. Mr Gavel for the Council: "…the discharging pipelines within the subject downstream easement does not have the capacity to convey the 1% AEP design requirement from the subject development site …. The 1% AEP is a design requirement for drainage systems that require On-site Detention as detailed in Council's controlling documents incl. Council's DCP 2011, Stormwater Disposal Policy 2020, Council's Engineering Design Guidelines 2018, Upper Parramatta River Catchment Design Handbooks Editions 3 & 4."
2. It is noted that the objections to the stormwater pipes is in 2 parts: 1. The stormwater pipe traversing the easement at 9-11 Weston Street has the capacity to take up to the 1% AEP overland flow. The surface flow in this area is in a storm event above the 1% AEP, or in excess of 1% AEP plus a pipe blockage. This stormwater pipe is shown on the Stormwater Concept Design plan no. SW204 rev F which forms the first page in Ex E (9-11 Weston St Easement). 2. The stormwater pipe traversing the easement at 12-16 Hope Street has the capacity to take up to the 5% AEP overland flow. The system of drainage proposed by the Applicant in this part of the easement is for the 1:20 year flood event to be contained within the stormwater pipes, and above the 1:20 year flood event (including up to and in excess of the 1:100 flood event) to be contained within the surface swale (12-16 Hope St easement).
3. In the following paragraphs, when quoting the experts or counsel, the quotes are either words 'to the effect of' or exactly as said.
4. Mr Gavel gave the following evidence: 1. Although he has had a limited time to consider the information in Ex D and Ex E, he has formed an opinion in relation to the matters raised therein. 2. The new plans (Ex E) as explained in Ex D, are inappropriate in as much as they show: 1. In relation to the 9-11 Weston St Easement as referenced by the longitudinal section E-E, the intent of removing part of the landscape area which forms part of another DA consent (on 9-11 Weston St) or carrying out works by increasing the size of the existing timber edge on the fence side by raising it by 40mm (also part of the same 'other' consent) are inappropriate. 2. In relation to the 12-16 Hope St Easement as referenced by the longitudinal Section G-G in Ex E, the intent is to build a 120mm high kerb to contain the emergency flows within the easement. This requires the carrying out of works. Mr Gavel's opinion is that this proposal is inadequate to the task as when the water goes through that fence it needs to be directed at 90-degree bends. Mr Gavel does not consider that the proposal would be successful in containing the emergency overland flow, and said words to the effect of: "There will be some overflow. And potential for erosion under the kerb leading to …. The easement width of 1.2m has not been achieved."
5. In answer to a question as to whether the onsite view was the first time Mr Gavel had been on site, he replied in the negative, and that he had been onsite previously, but not until after the conference of experts which formed Ex 3, and was filed on 6 May 2022.
6. In cross examination Mr Gavel was taken to Ex 2, tab 9, in reference to his Curriculum Vitae attached to Ex 3. In Ex 2, tab 9, p 284: "1.2 Consultants …… The design and certification of stormwater drainage and On Site Detention (OSD) systems in the City of Parramatta will only be accepted from persons having suitable professional accreditation. The following are considered to be acceptable accreditation for the purpose of stormwater drainage and OSD design and certification: a) A Professional Engineer registered with the National Engineering Register (NER) in Civil Engineering. b) A holder of Surveyors Certificate Accreditation in On-site Detention and Drainage Design (Institution of Surveyors, NSW and the Association of Consulting Surveyors, NSW) c) A member of Stormwater Register (Association of Hydraulic Services Consultants, Australia); and d) A Certifier accredited by the Building Professionals Board (under the Environmental Planning and Assessment Act 1979) in any of the following categories: B1, C1, C2, C3, C4, C5, C6, C7, C12, C15." And was questioned as follows, in words to the effect of: Mr Lazarus SC: "Your CV attached to the Joint Report is complete in so far as it contains all your qualifications and affiliations?" Mr Gavel: "Yes." Mr Lazarus SC: "In reference to par 1.2 (in Council's Development Engineering Guidelines - Ex 2, tab 9) your CV does not specify that you hold any qualifications set out in par 1.2 a), b), c) or d)?" Mr Gavel: "No I do not, and nor do I need to." Mr Lazarus SC: "Are you qualified under par 1.2 to design and certify?" Mr Gavel: "Not to design or certify." Mr Lazarus SC: "Under these Guidelines you are required to design and certify?" Mr Gavel: "That is correct."
7. In cross examination Mr Gavel was asked about Ex D and Ex F in relation to the area of the 12-16 Hope St Easement depicted in the longitudinal sections as A-A, B-B and C-C, and, it was put to him, in words to the effect of: Mr Lazarus SC: "These flows will still be contained so that it will not be spread beyond the 1.34m or 1.5m line: whatever it may be?" Mr. Gavel: "That is exactly my point. These flows do not have a right to go beyond 1.2m." Mr Lazarus SC: "Anyone in their right mind would not complain about a nuisance water flow by 10-20 cm?" Mr Gavel: "….It is not the nuisance value; it is the legal entitlement that the flows do not have any legal entitlement beyond 1.2m." …… Mr Lazarus SC: "Aside from the technical legal point, this is not a complaint of substance that is likely to impact on the assessment of 1% AEP and/or a blockage in the pipe?" Mr Gavel: "I have not raised the functionality but the legality of it." Mr Lazarus SC: "No issue with functionality - only legality?" Mr Gavel: "There may be an objection by the property owners." Mr Lazarus SC: "The assumption underlying your objections is that there is a 1:100 year flood, and there is a full blockage of the pipes?" Mr Gavel: "Yes." …… Mr Lazarus SC: "In relation to E-E, you consider the kerb as recommended by Mr Haddad could be eroded?" Mr Gavel: "Occurring on more than one occasion when the stormwater flows would be up against that kerb. It depends on the severity of significant events." Mr Lazarus SC: "If it is a properly constructed concrete kerb?" Mr Gavel: "There is no detail on the plan about how that would be constructed……There is nothing to suggest that it has anti-erosion qualities." Mr Lazarus SC: "What would be required?" Mr Gavel: "You would have to take greater detail in the design of the kerb: it needs to penetrate within the existing ground, and some level of reinforcement to withstand the Biblical flood event." …… Mr Lazarus SC: " You gave some evidence about turbulence and overflows in the 1:100 year event. That is not based on calculation - based on your experience?" Mr Gavel: "It is my opinion of 50 years' experience in the industry. You know instinctively. No calculations to suggest that it is adequate or inadequate."
8. Mr Lazarus requested Mr Haddad to explain the recommendation for a 120mm concrete kerb at longitudinal section E-E on Ex E, and Mr Haddad replied: "We looked at a ratio: velocity x depth in the 1:100 flood event = 0.1L/s….Water will flow through there with no issues at all."
9. Ms Sims re-examined Mr Gavel, firstly in relation to the DRAINS modelling (Ex 3 - Joint Report, appendix D, p 31: "Results for medium storm in critical 1%": Mr Gavel replied: "The DRAINS modelling has been provided previously. 61 L/s going through the pipe after OSD. I am not disputing that. However, we talk about emergency flow in the case of a pipe blockage down-stream of the subject site. Taking into consideration 212 L/s 223 would have been pulled back to 61L/s………Emergency flows which are to be taken into consideration: 9-11 - if the blockage is below 9-11 - all the flows have not been considered." Ms Sims: "DRAINS model: numbers on a page: where are the sources of water 223 and numbers on this page?" Mr Gavel replied: "0.212/m3 = 212L/s. 0.213/m3 leads to 0.011 bypass flows that are not directed into the OSD system. Allowance 15% bypass. Acceptable: 0.011, 11L/s leaving the site outside the OSD if known fundamental = 223L/s leaving the site. 0.014 at 9-11 leads to 0.129 going over the site. 129L/s + 0.014 = emergency flows 143 L/s leaving 9-11 site. Combined flows of both these sites going overland directed into 16 Hope Street. That proposed kerb is inadequate for the context.
10. Mr Haddad's response to Mr Gavel's evidence above: "The explanation is completely incorrect. The stormwater drainage system is designed to be a self-blending system, self-cleaning system. The other thing to have a look at when considering blockages is the surrounding environment; in a pipeline risk of blockage becomes high in a rural setting with trees. In an urban environment without trees there is nothing to suggest that system would be blocked. What Mr Gavel is suggesting is the blockage of the whole system. It is fully blocked and we have a 100 year flood event at the same time. Stormwater AS 3500.3:2018 recognises that pipes above 300mm - 322.5mm are unlikely to be blocked because they have trash screens (pollutant traps). To have this imaginary scenario - in all of my 25 years as a practicing engineer, I have not heard this before. There are no design guidelines requiring us to do this. We have provided the strata with a maintenance schedule. It is detailed to allow the system to be maintained, and for maintenance after every large rainfall event. The easement is 1.2m wide which is what Council required."
11. Mr Lazarus SC made the following final submissions: The case relates to the size of the second easement (12-16 Hope St Easement) and whether 225m pipe size is sufficient; and the emergency flow path. (Ref s 8.7 (2)(b) of the EPA Act and subcll 95 (3) & (4) of the EPA Regulation). 1. The statutory setting for these proceedings does not envelope an application or a modification to an application. Rather the Court must consider exercising the function of the consent authority and must consider whether the evidence or a level of satisfaction subscribed by the legislation has been met. 2. Ex 2, tab 12, p 375: the reference to the time period to satisfy the deferred condition of consent has been extended to 21 October 2023. 3. Ex 2, tab 12, p 374: Deferred Condition 2: subpar (i) has been met. In relation to subpar (ii), plans were submitted to Council for assessment and approval. The Court is in the position of the approver. The condition does not specify the criteria by which the satisfaction is to be reached. It seems to be a common agreement that the criteria are in various policy documents. Beyond that, the discretion you have is not constrained in any way. 4. Ex 2, tab 12, p 374, subpar (ii) second sentence: "The plan shall also demonstrate the easements functionality as an overland emergency flowpath from the subject site to Hope Street." 1. The important word is "functionality". There is nothing about what happens on the Site. 2. It also seems to be common ground between the experts that the 'emergency' needs the 1:100 flood event plus a blocked pipe. Mr Haddad has undertaken that analysis in both the 50% and 100% blockages. Nothing about a blockage in the OSD system itself. 3. Regarding the "functionality", certainly the plan must demonstrate some element of functionality but it does not require it in terms of complete satisfaction to a clinical standard. That brings into question those circumstances which are referable, e.g. likelihood or unlikelihood of there being a blockage when compliant with the 1:100 year flood event. It is a practical question when considering functionality. 4. The Court should take more than a simple mathematical approach in exercising its discretion as to whether that requirement of functionality has been satisfied in relation to the requisite standard. 5. Mr Haddad called Mr Gavel's assessment of 1% AEP event together with a total blockage of the pipe, to be an imaginary scenario. The OSD is a self-cleaning system. The surrounding environment was seen on the site view. Trees may lead to a blockage but there were no trees near the system. There is a maintenance schedule including trash screens to prevent blockages. It is in an urban setting. When you add all these things together you get to a state of satisfaction. 6. Ex 2, tab 12, p 374, par 2, subpar (iii): "A cross section of the overland flow path within the easement. A longitudinal section of the pipeline within the easement." 1. There has been an issue raised whether the second easement pipe (12-16 Hope St Easement) has been adequately sized: the calculations are only required at the Construction Certificate stage. We have provided those calculations at this stage. Council was happy for the consent to become operative without the calculations. (Ex 2, tab 12, p 375, second sentence in first paragraph). 2. Regarding assessment of the pipe in the 12-16 Hope St Easement: 1. Ex 2, tab 5, PDCP 2011, p 43 at principle P.8: the second sentence: "The site drainage network must provide the capacity to safely convey stormwater run-off resulting from design storm event listed in Council's Design and Development Guidelines" - it is the document of central importance. 2. Ex 2, tab 9, Guidelines, p 284, par 1.2: Mr Gavel is not qualified to design and certify OSD and stormwater drainage. Mr Haddad is so qualified because he holds the qualifications in par 1.2 (a), and par 1 and 2 on p 285: you have to design and certify both of them (OSD and stormwater drainage) to the extent they are relevant to inter-allotment drainage. 3. Ex 2, tab 9, Guidelines, p 289, par 4.2 - subpar 3, 4 and 6: there is no suggestion here or anywhere in these documents that overland flow is just for 'emergencies'. All it says is that it has to cater for overland flows in emergencies. 4. Ex 2, tab 9, Guidelines, p 294, par 5.1: Inter-allotment drainage (where a flowpath for flow in excess of the pipe capacity has been provided) designed to a 20 year event. There is no dispute between the parties that the pipes and overland flow together are designed to accommodate the 1:100 year flood event. Mr Gavel, however, has said that the pipes must be sufficient for the 1% AEP event. That proposition is directly contradicted by par 5.1 on p 294. Mr Haddad's opinion, in Ex 3 p 13 par (f) is that in his experience the requirement in par 5.1 has not only been required by this Council but "everywhere in the Sydney basin including Parramatta Council". 5. Ex 2, tab 9, Guidelines, par 2, p 297: Section 2: On-site Detention (OSD): is the only relevance to this particular question. No issue arises. 6. Ex 2, tab 9, par 3, p 303: Section 3 OSD Design: not in issue. 7. Ex 2, tab 9, par 3.6, p 308: Inter-allotment Drainage easement: par 3.6 calls up Table 5.1 on p 294. 8. The requirements for Deferred Condition 2 (ii) and (iii) have been satisfied. This conclusion is based on all of the policy documents that there really is no doubt and it is not open to the Court to require the pipe in the 12-16 Hope St Easement to satisfy the 1:100 ARI event. 9. Other matters of relevance: Ex 3, p 17, Mr Haddad stated: "The 1% AEP flows in the overland flowpath in excess of the pipe capacity is limited to 24L/s which is considered a minor flow that can be safely conveyed in the overland flowpath provided (and also requested by Council in the conditions of consent)." 1. The Applicant relies upon Ex E which are the plans SW204 Rev F and SW300 Rev F, and are to replace the plans in Ex B, Applicant's Class 1 Application, tab 11, plans SW204 Rev E and SW300 Rev E. 2. In relation to Ex D and Ex E, the concrete kerb as shown in the diagram on Ex E, plan SW300 Rev F - we accept that a development consent would be required to enable the concrete kerb to be constructed. 3. Emergency overflow issue: the definition of 'emergency' between the experts is a blocked pipe. It is a non-functioning OSD. The correct approach is not strictly mathematical. However, if you are to take a mathematical approach (Ex D) something that would inform your judgment, we submit is the 61L/s is the appropriate figure, rather than Mr Gavel's 213L/s. It would be absurd to require a fully developed piece of land to have available to it over adjoining land so far as they are within the 1.2m easement of sufficient capacity to handle the 100 year flood event on the assumption that the pipes are blocked and there is no functioning OSD. That was an imaginary scenario put by Mr Gavel, notwithstanding a functioning OSD and pipes. That is such a high threshold which is not required by any of Council's policies.
12. Mr Lazarus SC raised 3 legal issues: 1. Your satisfaction is subject to s 8.7(2)(b) and 4.16(3) of the EPA Act, and cl 95 of the EPA Regulation. It is our submission that this is not necessarily a 'yes' or 'no' answer based on the authority that your satisfaction could be provided conditionally. Bignold J held in Captain Cook Cruises Pty Ltd v North Sydney Council (2002) 126 LGERA 233; [2002] NSWLEC 243 ('Captain Cook Cruises') at [80] referencing s 91AA [66] as it then was: [84] .. "There was nothing in the language or purpose of s 91AA of the EPA Act that would preclude a consent authority from expressing its satisfaction in respect of a deferred commencement condition in a qualified or conditional manner", and, [90]…It was open to the council under (that section) to express a conditional or qualified satisfaction in respect of the deferred commencement condition. This decision has not been qualified in any way in any subsequent decision. 2. Development consent question - at least in relation to the kerb referenced in Ex D and E are area E-E that a development consent would be required. We submit at this stage of the enquiry you do not need to be satisfied that development consent needs to be granted. In this case there was no serious objection from Council's expert to the construction of the kerb otherwise than to say that the structure may be eroded. The kerb has been designed in response to Council's concern to prevent damage to the servient tenement, particularly the retaining wall at the rear of the 12-16 Hope St property. The kerb might be required to meet some mathematical calculation. There is a realistic prospect that a development consent would be obtained for these works. The question was raised that the servient tenement's consent would be required to lodge a development application for the kerb on the 12-16 Hope St Easement, and also the 9-11 Weston St Easement, or whether the servient tenement's consent could be compelled in reliance upon the dominant tenement's easement rights. 1. Conveyancing Act 1919, s 181A (1A) provides……"the expressions ….have the same effect as if there had been inserted in lieu thereof respectively the words contained in Part 3 of Schedule 8." The provisions give express rights to the dominant tenement to "go across and through the land…together with the right to enter upon the servient tenement …."to open the soil of the servient tenement to such extent as may be necessary provided that the grantee and the person authorised by the grantee will take all reasonable precautions to ensure as little disturbance as possible to the surface….." 2. In Lowe v Kladis [2018] NSWCA 130 ('Lowe'), Mr Lazarus relied upon - "[96] …the dominant owner has a commensurate right to enjoy the easement of carriageway free from substantial interference by a servient owner. In addition, the dominant owner has such ancillary rights as are reasonably necessary for the exercise or enjoyment of the easement (117 York Street Pty Ltd v Proprietors of Strata Plan No. 16123 (1998) 43 NSWLR 504 at 521-522). This is a common law principle but it has been applied to easements registered on the title to land under the Real Property Act 1900 (NSW). Thus, in Hemmes Hermitage Pty Ltd v Abdurahman (1991) 22 NSWLR 343, this Court held that the owner of the dominant tenement was entitled to go onto the servient tenement beyond the boundaries of a footway, to undertake works necessary to maintain the trafficability of the right of footway. [97] The ancillary rights of a dominant owner include, where appropriate, the right to obtain the written consent of the owner of the servient tenement to the lodgment of a development application by the dominant owner. In Sertari Pty Ltd v Nirimba Developments Pty Ltd [2007] NSWCA 324; (2008) NSWConvR 56-200, this Court held that such an order can be made where the development application is for the construction of improvements on the right of way which are reasonably necessary for the proper enjoyment of the easement…. [100] …….the ancillary right of the dominant owner to require the servient owner to consent to the lodgment of a development application raises two separate but perhaps related questions: (i) Is the proposed use of the carriageway by the dominant owner excessive, such that it is not authorised by the terms of the easement and is therefore unlawful? (ii) Does the proposed development by the dominant owner unreasonably interfere with the reasonable use of the servient tenement by the servient owner (or the persons entitled to a right of carriageway over the same land)?" 1. The aim of the proposed works in this case is to prevent flows of water in a serious flood event from entering upon the servient tenement, and to prevent damage to the servient tenement outside the easements. Because of the lie of the land and the slope of the ground, it would also achieve the purpose of our proprietorial rights without unduly impacting upon either strata development. 2. This is not a development (meaning the 'kerb') that is on an area of land which could be used for any other purpose. It could not be said to be impacting on the servient tenement. In any event, a development application would need to be made to gain consent for the proposed works, and if the servient tenements wished to do so, each of them could lodge a submission with Council. 3. The fact that further works might be required to meet the mathematical standards referred to in Ex D is not an impediment to the Court achieving a level of satisfaction that the easement has an emergency flow path. 1. Response to Mr Gavel: 1. In so far as the longitudinal section G-G in Ex D and E is concerned, Mr Haddad has put forward two options, either of which would achieve the requested mathematical standard - and one of which may be more intrusive that the other. In any event an appropriate condition could be imposed which would permit either of these options to be imposed. 2. Mr Gavel has questioned the size of the pipe at the longitudinal section E-E in Ex D and Ex E - this is the pipe in existence which is designed to the 5% AEP with provision for stormwater above the 5% AEP and the 1% AEP to be surface flow. We would submit that there is no real impediment in the extreme unlikelihood of the scouring or turbulence relied upon by Mr Gavel. Mr Gavel's opinion is speculative and should form no part of any assessment. These works which are proposed would contain the 'emergency' flow within the wall of the proposed kerb and the fence line. 3. The issues raised by Mr Gavel in Ex D and Ex E at longitudinal sections A-A, B-B and C-C on plan SW300 Rev F, are outside the 1.2m 12-16 Hope St Easement. The 1.2m easements are standard practice, as referred to by Mr Haddad. The actual construction, which is in existence for the easement from the Strata Plan on 9-11 Weston Street, slightly exceeds the width of 1.2m - as identified and objected to by Mr Gavel. As the structures are in existence at a width of .5m, and Mr Haddad has proved they are sufficient to take the 5% AEP in the pipe, and the 1% AEP by overland flow, we would submit the slight exceedance of the 1.2m in the easement is of no moment whatsoever in terms of 'satisfaction' under cl 95 of the EPA Regulation. In this scenario, the criticism of Mr Gavel should not be accepted.
13. Ms Sims made the following final submissions: 1. The question of the overland flow path which arises as a consequence of the Applicant's emergency overland flow path, you would not be satisfied with the evidence that has been presented in satisfaction of Deferred Commencement Condition 2 (ii) and (iii) of Schedule 1 of DA/267/2018B. The questions are: what flow is required to be accommodated? And what emergency flow is required to be accommodated? 2. In Ex 2, tab 12, p 374, Onsite Detention System, subpar (ii) the Applicant is required to demonstrate the easements functionality as an overland emergency flowpath from the Site to Hope Street. 1. What is the emergency? The combination of a blocked pipe and the 1% AEP flow? The outlet for the OSD is blocked and the water does not flow. By simply blocking the outlet pipe (e.g. plastic placed or caught over the trash screen) - if the outlet of the OSD is blocked the tank fills up and then it spills at 220L/s. This is not outside the realm of possibility. 2. The functionality: the physical form of the easement does not function sufficiently well to meet the test of functionality. The evidence is that further work is required for it to function in the way envisaged by the description in subpar (ii) of Deferred Commencement Condition 2 (ii) of Schedule 1. 3. In terms of the works on the 9-11 Weston St Easement, longitudinal section G-G in Ex D and Ex E, two options are proposed: 1. Raise the edge of the timber retaining wall with the consequence that the overland flow would spread across the edge of the easement to a distance of 0.8 m. The footpath on 9-11 Weston Street would be under water but what is the real impact on the people who live on that property? The overflow to the footpath would be a short-term impact. 2. Remove part of the footpath: What is the real impact on the residents of that property? 1. In terms of the works on 12-16 Hope St Easement by constructing a concrete kerb: the impacts have not been assessed. It is not clear if the residents want landscaping in that area of land. 2. I accept that along the side of the 12-16 Hope St Easement in the longitudinal sections A-A, B-B and C-C in Ex D and Ex E, there is a channel up to 1.5m. The formal easement is 1.2m wide. I cannot say that there is any interference with the enjoyment of the Hope Street site. But the tests of what is a nuisance is that it needs to be both substantial and unreasonable. 1. In relation to the legal points about: 1. Whether the Court could be conditionally satisfied: I am not aware of any case to the contrary of Captain Cook Cruises. 2. In respect of the proposed works in Ex D, I accept that a development application would be required, at least for the concrete kerb. However, satisfaction would be required for the development application. My submission is that in the circumstances of this case, the Court should not be satisfied and should not be satisfied conditionally because what is proposed does not accommodate the emergency flows. Secondly, there is the impact of the proposed development which is not known on these two properties. 3. I do not dispute the legal rights in relation to the easement, and necessarily rights in terms of the test of whether the works that are proposed are reasonably necessary without undue impact on the servient tenements. This is the question the Court should consider, and it does not have sufficient information at the present time: 1. We do not know what the works are to be - exactly. 2. We do not know the impact of those works on the servient tenements. 1. The conditional consent is subject to the Court's satisfaction that the Applicant can obtain a development consent for the works, together with owners' consent. 2. The Court should say that it is not satisfied that the Applicant has demonstrated the easements' functionality as an emergency overland flowpath. 1. In relation to the pipe size for the 12-16 Hope St Easement: it is sufficient to accommodate the 5% AEP flow but not the 1% AEP flow. What is intended here: the OSD system is required to accommodate the 1% AEP across the whole Site. The OSD releases the stormwater at a defined rate. The rate at which the OSD discharges needs to be used to design the pipe. The pipe for the 9-11 Weston St Easement can cope with flows up to 1% AEP, but what happens is that pit at the edge of 9-11 Weston St Easement duly discharges the stormwater, and it flows across the land into that overland flowpath on 12-16 Hope Street. That is why Council's Policy requires the pipe to be able to accommodate the 1% AEP for the whole length of the pipe. Ex 2, tab 12, p 374 - "(ii) …. demonstrate the easements functionality as an overland emergency flowpath ": 1. The pipe's functionality as an overland emergency flowpath. 2. Pipeline and overland flowpath but the overland flowpath is emergency flowpath. 1. Scenarios: 1: 1% AEP plus blockage of pipe, 2: Rainfall up to 1:100 rainfall event. 2. Ex 2, tab 9, Guidelines: 1. Section 1: Drainage; par 1.0 Introduction, p 283: "This guideline is intended to set out Council's requirements for the design of stormwater drainage and other engineering elements associated with development. It is not intended to be a comprehensive design manual nor a stand-alone document but rather to be read in conjunction with relevant instruments, policies, codes, industry guidelines and standards including: …… p) Stormwater Disposal Policy." 1. Section 5.0 Stormwater Drainage Design Standards, and par 5.1 Average Recurrence Intervals: needs to be read in conjunction with the Stormwater Disposal Policy, etc. The relevant reference is when you have an OSD system, the system is pipe only. 1. Ex 2, tab 10, PDCP 2011, Stormwater Disposal Policy, p 315: Storm Water Disposal - only applies when the development requires inter-allotment drainage. 2. Ex 2, tab 10, PDSCP 2011 Policy - Definitions, p 321 - "On-site Detention (OSD) - a stormwater management system designed to collect and detain water before releasing it at a controlled flow rate by gravity to Council's stormwater infrastructure. The sole purpose of OSD is to reduce flooding." …… "Inter-allotment drainage easement - see para (b)(iii) above." …. The OSD system includes the inflow required to take water into the tank, and out of the tank, and potential overland flow. The pipe downstream of the OSD should be sized to take the outflow from the OSD, i.e., 1% AEP. 1. Ex 2, tab 9, Design Guidelines, par 4.2 Private Drainage Easement; 289, particularly pars 3 and 4: "The system shall be designed to sufficiently convey all runoff from the development site and when draining developments with OSD shall be designed to cater for emergency overflows of the OSD system in all storms up to and including the 100 year ARI storm event. Where the system is proposed through multiple properties, the system shall be designed to cater for any additional flows which can be directed into the system from those sites." 1. The Court would not be satisfied that the pipes are sufficiently sized. The 12-16 Hope St Easement pipe is 225mm and should be 300mm.
14. Mr Lazarus in reply: In relation to Ms Sims' submissions regarding the proposed works as set out in Ex D and Ex E, it was a reference to present functionality of the system: 1. Ms Sim cannot possibly mean presently functional because there is no development on the Site. It is a theoretical exercise that is contemplated by this condition: it is forward looking that is required. It can include an assessment of future works as part of an overland flowpath. 2. I disagree with Ms Sim's submission that properly speaking the merits of the various items of works could not be appropriately assessed: it is true there has not been a fulsome assessment because there is no development application before the Court. Nor does there need to be. We are talking about the capacity of the overland flowpath to accommodate these emergencies flows. If the Court is satisfied the sort of development application would be contemplated, then a conditional satisfaction could follow. It is a low threshold at this level. 3. In relation to the submission regarding longitudinal section E-E (Ex D and Ex E) on 12-16 Hope Street, 'the owner may wish to put landscaping on that area', you cannot infringe the Applicant's right to use the easement. 4. In relation to the size of the pipe for 12-16 Hope St Easement: it was submitted as a matter of construction that any overland flowpath must be an emergency overland flowpath. There is nothing in the document to limit the construction of the overland flowpath in this way. And the condition itself (Ex 2, tab 12, p 374) that contemplates an overland flowpath could in part at least meet the requirements of Council's policy. 5. The Guidelines have to be read subject to the Policy. The application of these various documents is determined by the PDCP 2011. It is quite clear (Ex 2, tab 5, p 43) from Design Principle P.8 "the capacity to safely convey stormwater run-off resulting from design storm events listed in Council's Design and Development Guidelines". There is nothing in the Policy itself that would preclude the detention system being a combination of pipe and overland flow within the system to satisfy the 1% AEP. We refer to the proposition that one could borrow the definition of 'inter-allotment drainage' and incorporate it into the Guidelines. That is contrary to what the Guidelines say, but also because the Guidelines deal separately with the question of inter-allotment drainage. 6. Returning to the inter-allotment drainage system: Ex 2, tab 9, p 294, Section 5: Stormwater Drainage Design Standards, 'The following average recurrence intervals (ARI) shall be used for stormwater drainage design relating to development: …… "Inter-allotment drainage (where a flow in excess of pipe capacity has been provided) Design ARI (Years) 20 Inter-allotment drainage (pipe only) Design ARI (Years) 100 ……" Inter-allotment drainage includes the flowpath for flow in excess of the pipe capacity.
15. The Court would uphold the Applicant's appeal and be satisfied that Deferred Commencement Conditions 1 and 2 of Schedule 1 of development consent DA/267/2018B granted by the Respondent on 23 October 2019 have been satisfied.

Findings

1. The issues in this case are: 1. The dispute between the parties is that the Applicant has designed a system as a combination of OSD, pipe and overland flow path to cater for storm events up to and including the 1% AEP plus emergency flows; whereas the Council considers that the OSD and pipe system should be designed to cater for storm events up to and including the 1% AEP, and the overland flow path should be reserved for emergency flows. 2. What is the correct test to apply in determining satisfaction with Deferred Condition of Consent No 2 (ii) and (iii) in Schedule 1 in relation to DA/267/2018B? 3. In applying the test, is the evidence sufficient to satisfy the Court in relation to Deferred Commencement Condition of Consent 2(ii) and (iii) in relation to DA/267-2018B, and particularly in relation to the functionality of the stormwater drainage system?
2. When I refer to 'emergency flows' I am adopting part of the definition as set out in par 19 above by Ms Sims: " ….emergencies where either the pipeline is blocked or the rainfall is greater than 1% AEP". Ms Sims extended the definition of emergency flow to: "Or there is a total blockage in the OSD, or pipe with an exceedance of the 1% AEP event" par 19. This latter part of the definition of emergency flows as to a 100% blockage in the OSD or pipe was an issue between the experts. Mr Gavel agrees with the 'emergency' flow is as described by Ms Sim above. Mr Haddad considers that the concept of a total blockage in the OSD or pipe together with a flow above the 1% AEP is 'unlikely' in his experience and in an urban setting such as this Site with its easements. Mr Haddad also considers that in assessing the possibility of a partial or total blockage the test of 'likelihood' or unlikelihood' of it happening should be taken into account, and he is of the opinion that a 1% AEP plus a total blockage of the pipe is 'imaginary' in the circumstances of an urban system without nearby trees or other possible impediments to the pipes.
3. I therefore consider the 'emergency flow' consists of a flow at or above the 1% AEP plus a partial or full blockage in the pipe. I accept Mr Haddad's evidence that the OSD has been designed to have regular maintenance and that there should not be a total blockage in the OSD at the same time there is a storm event above the 1% AEP.
4. The design of the stormwater drainage system proposed by the Applicant is as follows: 1. The OSD collects offsite and onsite overland flow, and has capacity to store it up to 1:100 flood event. 2. The pipe from the OSD across the 9-11 Weston St Easement is 300mm in width and is designed to carry stormwater up to and including the 1% AEP. The overland flow is designed to carry the emergency overflow. 3. The pipe from the 9-11 Weston St Easement to, and through, the 12-16 Hope Street Easement, is designed to carry stormwater up to and including the 5% AEP, and the drainage swale within the easement is designed to carry the 1% AEP above the 5% AEP flow plus the emergency stormwater overland flow to Council's drainage pit in Hope Street.
5. The Applicant tendered Ex D and Ex E recommending further works to the easements as follows: 1. 9-11 Weston St Easement: 1. In answer to Mr Gavel's concern, raised on the site view, that the overland flowpath contained floatable material (timber mulch) which does not conform to the design criteria in par 3.6.1 (Ex 2, tab 9, p308), the bark or timber mulch be replaced with pebbles or similar material which will not float in a storm event. 2. The narrow section of the pathway is not wide enough to carry the emergency flows - therefore the existing timber edge on the fence side be raised by 40mm. 1. 12-16 Hope St Easement: on that part of the easement which is parallel with the rear fence, a concrete kerb 120mm high to contain the overland flow in accordance with the concept design in Ex E (plans SW300 Rev F and SW204 Rev F). I note that this kerb is 1.2m from the rear fence, and within the raised area which has a width of 4.6m supported by a block retaining wall at the rear of 12-16 Hope St.
6. I prefer the application of the relevant documents as relied upon by the Applicant. The policies/guidelines to be applied are as follows: 1. PDCP 2011, Part 3, Development Principles par 3.3.6.1, and Stormwater Drainage - Design Principles, P.6, P.7 and P.8 (Ex 2, tab 5, p 43). The policy documents are called up in different ways and for different purposes: 1. P.6 - references adequate provision for stormwater runoff in accordance with the current Guidelines. 2. P.7 - references the design of the OSD as outlined in the Handbook. 3. P.8 - the drainage work must provide the capacity to safely convey stormwater run-off. The Applicant relies upon the Table in Ex D, p1. 1. City of Parramatta Stormwater Disposal Policy, (Ex 2, tab 10, p 321) the definition of "Inter-allotment drainage easement" does not exclude surface drainage. Council relied upon this definition as meaning that the pipes leading from the OSD to Council's stormwater drainage system must have capacity to accept up to and including the 1% AEP. 2. Development Engineering Design Guidelines (Ex 2, tab 9): 1. Section 1: Drainage, p 283: This guideline is intended to set out Council's requirements for the design of stormwater drainage…..and is to be read in conjunction with relevant instruments, policies, codes, industry guidelines and standards, including ….d) Stormwater Disposal Policy. 2. Section 4, par 4.2, p 289 Private Drainage Easement - particularly par 3: "The System shall be designed to sufficiently convey all runoff from the development site and when draining developments with OSD shall be designed to cater for emergency overflows of the OSD system in all storms up to and including the 100 ARI storm event." In the Applicant's case, this 'System' includes the stormwater pipe plus overland flow to establish the design of stormwater disposal. In the Council's case, the pipe should be large enough to contain up to the 100 ARI storm event to Hope Street, as it discharges from the OSD. The 9-11 Weston St Easement pipe is sufficient for this purpose, but the 12-16 Hope Street Easement is not, and it relies on the 1% AEP above the 5% AEP being conveyed in the overland flow path. 3. Section 5: Stormwater Drainage Design Standards; on p 294: 1. The Applicant relies upon the Table 5.1: Average Recurrence Design Standards: and in particular the size of the pipe (5% AEP) where for inter-allotment drainage the flow path for flow in excess of the pipe capacity has been provided. 2. The Council relies upon the relevant control as the one for the pipe to contain stormwater flow to 1% AEP, without the necessity for an overland flow path. The Council considers that the overland flow path is only relevant for emergency flows. 1. Section 3, par 3.6: Inter-allotment Drainage easement, p 308, subpar "a) The inter-allotment drainage system within the easement shall be designed to cater for the 1% AEP storm event and includes a surface swale to control flows in cases of surcharge". 1. Upper Parramatta River Catchment Trust - On-site Stormwater Detention, 4th Edition: 1. The Applicant's case is that this document is only relevant in so far as it applies to the OSD drainage system, and that is not the subject of these proceedings. It is the capacity of the pipes which Council is questioning. 2. On the other hand, Council relies on the Glossary of Terms on p 81, and in particular: "Overland Flowpath: Surface drainage system that caters for minor flow from an upstream catchment. Also, the drainage system that caters for surcharges from the OSD storage in events larger than the 100 year ARI flow or when a blockage occurs." 1. I note the definition of OSD: "On-site Stormwater Detention temporary storage of stormwater generated within the site so as to restrict the discharge leaving the site to a pre-determined rate." 2. In Ex 1 - SOFAC, Council relies upon the Handbook in particulars 3 (c), (d) and (e) but it does not question the OSD, except in submissions on the basis of a blockage in the OSD. Further particular 3 (h) and (i) press the point of the 12-16 Hope St Easement containing a pipe of 225mm width when Council considers that the correct size of the pipe would be 300mm in diameter.
7. In relation to the experts, I prefer the evidence of Mr Haddad. Mr Gavel appears to have taken the view that the drainage system is not satisfactory because it does not convey the stormwater up to and including the 1% AEP via the OSD and then by pipe sized at 300mm, down to Council's drainage system in Hope Street. In applying the policies and guidelines, the system of stormwater drainage is able to be a combination of pipe sufficient to take a 5% AEP (225mm in this case) together with up to and including the 1% AEP by overland flow path.
8. In this case, the pipe in the 9-11 Weston St Easement is 300mm, and its overland flow path is sufficient to convey emergency flows. The pipe in the 12-16 Hope St Easement is 225mm which caters for the 5% AEP, and its overland flow path is sufficient to convey the 1% AEP above the 5% AEP plus the emergency flow.
9. In relation to the proposed 'new' works in Ex D and Ex E: 1. I note that Mr Gavel did not inspect the site until after the Joint Report (Ex 1) which was filed on 6 May 2022, and before the commencement of the hearing. Hence Mr Gavel did not notice the floatable timber mulch on the overland flow path of 9-11 Weston St Easement prior to the Joint Report, and did not raise it until the on-site view on the commencement of the hearing. Nevertheless, Mr Haddad has taken the point raised by Mr Gavel and undertaken to replace the floatable material with non-floatable pebbles. 2. In the 9-11 Weston St Easement, the narrow path is not wide enough to carry the emergency overland flow. Mr Haddad has recommended raising the existing timber edge on the fence side by 40mm as a minimum to achieve the depth to convey the overland flow arising from an emergency event. By raising the existing timber edge the emergency flow will be contained within the overland flow path. 3. In the commencement of the 12-16 Hope St Easement, the emergency flow would extend beyond the 1.2m easement into part of the 4.6m area of soil supported by the block retaining wall. Mr Haddad has suggested the construction of a 120mm concrete kerb as set out in Ex D and Ex E to contain the flows within this part the easement.
10. In relation to Deferred Commencement Condition (2) (ii), I find that the system for stormwater drainage within the 9-11 Weston St Easement and 12-16 Hope Street Easement is functional to convey up to the 1% AEP together with an emergency flow. The evidence of Mr Haddad, together with the plans in Ex B, tab 11, and Exs D and E, demonstrate the easement's functionality as an emergency flowpath from the Site to Hope Street.
11. I accept that the additional works recommended by Mr Haddad in Ex D and Ex E will improve the containment of the overland flow within the easements' flow path: 1. On 9-11 Weston Street (noting the flow outside the 1.2m easement is shallow and for a limited duration, the footpath is at the rear of the residential unit block and not likely to have pedestrian traffic in times of emergency stormwater flows); and 2. On the 12-16 Hope Street from the entry point to the boundary fence when it flows directly downhill to Council's stormwater system in Hope Street. I do not accept Council's objections which were in 2 parts: 1. The area contained within the 4.6m wide block retaining wall. The recommendation to construct a 120mm high kerb to contain the flow between 5% AEP and 1% AEP and the emergency flow is sound. The Conveyancing Act 1919, s 181(1A) and Pt 3 of Sch 8 give express rights to the dominant tenement to enter the servient tenement to carry out works relevant to the rights arising from the grant of the easement. From the on site view, and the placement and size of the proposed works. I do not believe that the proposed works will unreasonably interfere with the reasonable use of the servient tenement by the servient owner (Lowe [96], [97] and [100]. 2. The longitudinal sections A-A, B-B and C-C in Ex D and Ex E: Council's objects to the overland flow not being contained within the 1.2m easement, but the overland flow path is between 2 walls which are 1.5m apart. There is no suggestion that the 1% AEP and the emergency flow cannot be contained within the 2 walls. To build a third wall 30mm inside the outer wall does not make any practical sense.
12. The Council raised the issue of owner's consent to the proposed works. At this stage the owner's consent has not been sought, or refused, and if it was refused, the Applicant could rely upon Lowe at [97].
13. The Council objected to the Applicant's case that the Court could express its satisfaction in respect of the Deferred Commencement Condition No. 2 (ii) and (iii) in a qualified or conditional manner. The Applicant relied upon the decision of Bignold J in Captain Cook Cruises at [80] referencing for former s 91AA in [66], and applying [84] and [90].
14. I accept the Applicant's submission that there is a reasonable prospect that development consent would be granted, and indeed that the minor works on 9-11 Weston St may be able to be carried out within the grant of the easement without the necessity to obtain development consent.
15. I note that the Covid-19 Amendments have the impact of extending the date for compliance with the Deferred Commencement Condition in DA/267/2018B to 21 October 2023.
16. The Applicant had the right to appeal Council's deemed refusal of its application to satisfy the Deferred Commencement Condition No. 2 (ii) and (iii) in DA267/2018B in accordance with subss 8.7(1) and (2)(b) of the EPA Act, and cl 95 of the EPA Regulation.
17. In accordance with s 39(2) of the LEC Act, I will uphold the appeal, and I am satisfied with the Applicant's compliance with Deferred Commencement Condition No. 2 (ii) and (iii) in DA267/2018B conditional upon the Applicant carrying out the following works: 1. Replace the timber mulch on the easement flow path in 9-11 Weston Street with pebbles to prevent the timber mulch floating and causing a blockage downstream in an emergency stormwater event. 2. Raise the timber edge on the fence by 40mm in 9-11 Weston Street to contain the emergency flow on the flow path within the 1.2m easement. 3. At the rear of 12-16 Hope Street, construct a 120mm concrete kerb within the easement in accordance with Ex D and the plans in Ex E (SW300 Rev F and SW304 Rev F) to contain the 1% AEP and the emergency overland flow within the 1.2m easement.
18. The Court notes that: 1. On 21 February 2022, Parramatta City Council approved Modification Application PAN-182032 to correct minor errors and misdescriptions in Deferred Commencement Condition 1 of Schedule 1 of DA/267/2018, now DA/2672018B.
19. The Court orders that: 1. The appeal is upheld 2. In accordance with s 39(2) of the Land and Environment Court Act 1979, Deferred Commencement Condition No. 1 and 2 in DA/267/2018B is satisfied conditional upon the Applicant carrying out the following works: 1. Replace the timber mulch on the easement flow path in 9-11 Weston Street with pebbles or like material. 2. Raise the timber edge adjacent to the rear fence by 40mm within the easement at 9-11 Weston Street. 3. Construct a 120mm concrete kerb in accordance with Ex D and the plans in Ex E (SW300 Rev F and SW204 Rev F) within the easement at the rear of 12-16 Hope Street, Rosehill. 1. Exhibits are returned with the exception of Exhibits B, D, E, 1, 2 and 3 which are retained.

Amendments 20 July 2022 - Amendments made to Order No.2 of the decision pursuant to judgment Weston Investment Group Pty Ltd v City of Parramatta Council (No 2) on 19 July 2022. DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 20 July 2022